Orthodontics is a specialized area of dentistry in which therapeutic forces are applied to move maloccluded teeth to proper positions. The practice of orthodontics is supervised by a trained practitioner (e.g. orthodontist), who uses one or more orthodontic appliances to impart corrective forces directly to the teeth or stimulate or re-direct functional forces in the mouth to move teeth. Orthodontic treatment can provide a number of beneficial outcomes, including improved bite function, better hygiene and ease-of-cleaning, and enhanced facial aesthetics.
Fixed appliance therapy is one common type of treatment that involves attaching tiny slotted appliances called brackets to the teeth and coupling (or ligating) a resilient arch-shaped wire to the bracket slots. Upon installation, the wire shape is initially deflected to assume the crooked shape of the patient's dentition. Over time, however, the wire applies gentle corrective forces to the teeth as it returns to its original shape, thereby stimulating tooth movement toward desired finish positions. This process is generally repeated with progressively larger wires, with occasional adjustments to the wire made as needed, until the teeth positions are satisfactory to the practitioner.
One of the primary challenges with fixed appliance therapy is its reliance on accurate appliance placement on the tooth surface to move the teeth to desired finish positions. For example, if a particular bracket is located one millimeter too high on a certain tooth, then the wire would translate that tooth downward such that its final position is one millimeter too low. In this sense, these orthodontic appliances serve as precision handles to move teeth, and must be bonded to their respective teeth with great attention to appliance position on each tooth.